Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!weretis.net!feeder4.news.weretis.net!usenet.ukfsn.org!not-for-mail From: Martin Gregorie Newsgroups: comp.lang.java.programmer Subject: Re: O.T. optimising file placement Date: Fri, 24 Feb 2012 01:49:39 +0000 (UTC) Organization: UK Free Software Network Lines: 34 Message-ID: References: <3gm7k7lgroqn30g0nd7lqgsqo60hq02em1@4ax.com> NNTP-Posting-Host: 84.45.235.129 Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Trace: localhost.localdomain 1330048179 11429 84.45.235.129 (24 Feb 2012 01:49:39 GMT) X-Complaints-To: usenet@localhost.localdomain NNTP-Posting-Date: Fri, 24 Feb 2012 01:49:39 +0000 (UTC) User-Agent: Pan/0.135 (Tomorrow I'll Wake Up and Scald Myself with Tea; GIT 30dc37b master) Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:12290 On Thu, 23 Feb 2012 16:39:42 -0800, Lew wrote: > > I think we can all agree by now that that is not true. > Unlike some, I take a good deal of interest in what my machines are up to, so I was quoting what I see using top on my Linux systems. During normal operation there is very little activity on my laptop except from the programs I'm actively using unless, as you say, logwatch/smartd/ rkhunter/updatedb get run by atd, but on a reasonably quick machine they don't run for long. Of course, the house server is a different case, since it has several 24/7 services on it, but again its only heavy, continuous disk activity is overnight when it runs backups/logwatch/smartd/updatedb. Apart from that requests that wake up Postfix/Spamassassin/Apache/or ftpd/sshd are pretty sporadic and the disk LED flashes are best described as intermittent. The longest continuously busy time on either machine is during backups and even there there precious little contention since rsync or tar+gzip since the only stuff being written to the disk its reading from are backup logs. Same applies to software update sessions. To the best of my knowledge (and watching top) none of yum, rpm, tar, gzip or rsync are multi-threaded: rsync is probably using poll() based async i/o but from top and observed behaviour none of the others seem to do that. In fact the only long-running programs on my systems that I know to be multi- threaded are Apache, Postgres, SA and Postfix. -- martin@ | Martin Gregorie gregorie. | Essex, UK org |